Surgical sutures having attached surgical needles are well known in the art and provide a fundamental and essential means for various wound closure applications, including for example, approximating and closing incisions and lacerations. It is desirable to coat surgical needles with lubricious coatings to facilitate the passage of the needle through various types of tissues for multiple passes. Ease of penetration of the surgical needles through tissue is a critical, required property and is known to facilitate a wound closure procedure by providing the surgeon or medical professional with consistent performance during the suturing or wound closure process in which the needle readily passes through tissue with a minimal amount of force applied. Such surgical needles in combination with the skills of the surgeon are known to produce superior patient outcomes. Surgical needles are conventionally coated with a variety of known silicone-based coating solutions. The coating solutions may be applied in a variety of ways including dipping, spraying, brushing, etc. The needles may be singulated by mounting on strips prior to coating or may be batch coated. Batch coating processes typically are dipping processes wherein a batch of needles is placed in a wire basket, and then the basket and needles are subsequently immersed in a bath containing a liquid silicone coating composition. The basket containing the wet needles is subsequently removed from the coating bath and excess silicone is drained from the needles to the extent possible. Then the batch of wet needles is transferred to a suitable shallow container such as a tray for further additional conventional processing including curing and interim packaging. Although batch coating processes provide an adequate means to apply silicone coatings to a large number of surgical needles, there are several deficiencies associated with the use of these coating processes. First of all, the needles must be handled and moved after the batch coating application when the coatings are still wet to subsequent steps in the coating process including, for example, curing. It is known that handling needles having wet silicone coatings can result in damage to the integrity of the coatings resulting in coating defects such as globbiness and/or discontinuity in the coating. These defects can adversely affect the penetration performance of the surgical needles. Additionally, in a batch dipping process it is known that the wet silicone coatings can withdraw from the piercing tips of the needles due to the surface energy and low viscosity, which provides ample mobility to the silicone coating solution. The decreased amount of silicone coating on the piercing tips is a major factor associated with adverse needle penetration performance. Another disadvantage of the existing bulk dip-coating silicone coating processes is that they are known to be inefficient due to excess usage of expensive silicone coating solutions. A significant disadvantage of such existing processes relates to the associated economic inefficiencies in the manufacturing process resulting from significant numbers of needles having deficient or defective coatings which must be identified and discarded.
Accordingly, there is a need in this art for novel silicone coating processes that can be used with batch needle manufacturing processes and which provide superior needle coatings and associated improved needle performance, as well as manufacturing and cost efficiencies.